Hyderabad: The outlets of major stormwater drains are connected to lakes, which have been established in residential zones. The existing stormwater drains (SWDs) in these areas are choked with debris from construction activities.
The area under the erstwhile Municipal Corporation of Hyderabad was 170 sq km. After 12 circles were merged to create the Greater Hyderabad Municipal Corporation (GHMC), the area increased to 625 sq km. But the stormwater drains catered to the original 170 sq km were not proportionately increased.
Moreover, the stormwater and the sewage channels both drain into the lakes. So, Kapra lake, for example, receives grey water from the Kowkoor Shaili Gardens as well as water from all of Balajinagar drains.
If there is heavy rainfall, the only outflow for areas such as Madhapur and Gachibowli is the Durgam Cheruvu. Chemical waste from Nacharam drains into Uppal Cherruvu. Similarly, Alwal Cherruvu, Mini Tank Bund-Safilguda, Ramakrishnapuram lake-RK Puram, and Trimulgherry lake receive sewerage inflows from the neighbouring residential zone.
“The city suffers from an improper and inefficient sewerage system with an average network access of only 58 per cent, with 70 per cent on MCH (core city) area and only 20 per cent in surrounding municipalities. This is a highly unsanitary situation given that most developed countries have a 100 per cent sewage network. The functioning of the network of urban lakes has deteriorated rapidly as they have been encroached upon and polluted, and linkages have been blocked,” said environmentalist Subba Rao.
The city was originally planned to follow a natural drainage pattern and interconnected lakes were built to collect the water for ground water recharge and meet the city’s water requirements, with the overflow reaching River Musi or Hussainsagar.
However, modern development of Hyderabad, like with many cities, has ignored this sound practice, as a result citizens face many problems that could have been avoided if there had been proper planning. as in the past.
History of floods in Hyderabad
The city has witnessed major urban floods in 2000 and 2008, with annual rainfall of Hyderabad at 800 mm per year
2000 - August 23, 24
There was continuous down pour for four days. The city recorded 24.5 cm rain, about 1/3 rd of the yearly average in Hyderabad. Many tanks in and around the city breached and several low-lying areas were submerged.
2008 - August
Again the city witnessed heavy rainfall for 36 hours, recording 22.07 cm, and caused 17 deaths.
2016 - Sept. 21, 22
In 48 hours the city received 17 cm of rainfall, localities like Bandari, Deepthi Sreenagar and many low lying were submerged for days.
2017 - August 24, 25
An total average of 12 cm of rainfall was received.
